// $Id: FigPolyHandler.java 1153 2008-11-30 16:14:45Z bobtarling $
// Copyright (c) 1996-2006 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies.  This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason.  IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
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package org.tigris.gef.persistence.pgml;

import org.tigris.gef.presentation.FigPoly;

import org.xml.sax.Attributes;

import org.xml.sax.helpers.DefaultHandler;

/**
 * The handler for elements in PGML files representing FigPoly objects.
 */
public class FigPolyHandler extends BaseHandler {
    /**
     * The Fig for the poly.
     */
    private FigPoly poly;
    int _x1, _y1;

    /**
     * @param parser
     *                The PGMLStackParser for the diagram that contains this
     *                FigGroup
     * @param thePoly
     *                The object corresponding to the element being parsed
     */
    public FigPolyHandler(PGMLStackParser parser, FigPoly thePoly) {
        super(parser);
        poly = thePoly;
        _x1 = 0;
        _y1 = 0;
    }

    /**
     * Override the getElementHandler in {@link BaseHandler BaseHandler}. We
     * interpret the attributes of sub-elements moveto and lineto immediately as
     * line coordinates and add these as line segments to the FigPoly object.
     * The function then returns null; the elements are skipped.
     * 
     * @see org.tigris.gef.persistence.pgml.BaseHandler#getElementHandler(
     *      org.argouml.gef.HandlerStack, java.lang.Object, java.lang.String,
     *      java.lang.String, java.lang.String, org.xml.sax.Attributes)
     */
    protected DefaultHandler getElementHandler(HandlerStack stack,
            Object container, String uri, String localname, String qname,
            Attributes attributes) {
        if (qname.equals("moveto")) {
            String x1 = attributes.getValue("x");
            String y1 = attributes.getValue("y");
            _x1 = (x1 == null || x1.equals("")) ? 0 : Integer.parseInt(x1);
            _y1 = (y1 == null || y1.equals("")) ? 0 : Integer.parseInt(y1);
            poly.addPoint(_x1, _y1);
        } else if (qname.equals("lineto")) {
            String x2 = attributes.getValue("x");
            String y2 = attributes.getValue("y");
            int x2Int = (x2 == null || x2.equals("")) ? _x1 : Integer
                    .parseInt(x2);
            int y2Int = (y2 == null || y2.equals("")) ? _y1 : Integer
                    .parseInt(y2);
            poly.addPoint(x2Int, y2Int);
        }
        return null;
    }
}
